cardioid
noun, adjective
cardioid is a noun meaning “An epicycloid with exactly one cusp; the plane curve with polar equation ρ=1+ cos ,θ - approximately heart-shaped” (English Wiktionary, September 2026). It is spelled C-A-R-D-I-O-I-D, and it appears about once in every 18 million words in written English (wordfreq, 2021 data). The plural of cardioid is cardioids.
What does cardioid mean?
noun
- 1
An epicycloid with exactly one cusp; the plane curve with polar equation ρ=1+ cos ,θ - approximately heart-shaped
adjective
- 1
Having this characteristic shape
- 2
sensitive in front, but not behind or at the sides
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
How do you pronounce cardioid?
- US
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: En-us-cardioid.ogg, Wikimedia Commons (author and licence on each file's page).
Forms of cardioid
- cardioids plural
- more cardioid comparative
- most cardioid superlative
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
How common is cardioid?
Cardioid appears about once in every 18 million words in written English, the 127,184th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
Cardioid in Spanish, French, German and Portuguese
In the sense epicycloid with one cusp:
| Language | Words |
|---|---|
| French | cardioïde |
| German | Kardioide, Herzkurve |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does cardioid come from?
By surface analysis, cardi- + -oid.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).